Liquid-impelling apparatus.



PATENTED MAY 29, 1906.

. W. STARRETT.

D LIQUID IMPELLING APPARATUS. APPLICATION FILED JUNE 12. 1903. RENEWED NOV.20, 1905.

No. 821,677. PATENTED MAY 29, 1906. D. W. STARRETT. LIQUID IMPELLING APPARATUS.

APPLIOATION FILED JUNE 12. 1903. RENEWED NOV. 20, 1905.

2 SHEETS-SHEET 2.

my. 91 13 7 I wammw. j m 2W air would otherwise have to undergo.

propelled to a greater height or to a longer DANVILLE W. STARRET'I, OF OAKLAND, CALIFORNIA.

LIQUID-'EMPELLING APPARATUS.

Specification of Letters Patent.

ratenteu May 29, 1906 Application filed Tune 12,1903. Renewed November 20,1905. Serial No. 288,273.

10 (ML whom it, may concern.-

Be it known that I, DANVILLE W. STAR- RETT, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Liquid-Impelling Apparatus, of which the following is a specification. My invention relates to compressed-air pumps, the object of my invention being to provide an apparatus of this character by which water or other liquid can be raised or distance than heretofore without proportionately increasing the pressure of the compressed air which is used for that purpose, thereby effecting economy in the strength of the pipe and other apparatus used for conducting the water or other li uid and also in the power for compressing the air; also effecting economy bythe avoidance of undue heat due to the great compression which the In the accompanying drawings, Figure 1 is a front view of one form of the apparatus. Fig. 2 is a side view, on an enlarged scale, certain parts being broken away. Figs. 3 and 4 are views similar to Figs. 1 and 2 of a modified form of the invention. Figs. 5 and 6 are horizontal sections on the lines a a b b of Fig. 4. Fig. 7 is a vertical section of an experimental device illustrating the principles of the invention.

Referringto the drawings and considering first the modification illustrated in Figs. 1 and 2, 1 represents a double-acting air-com- I ressor having a piston 2. Spring-con trolled valves 31 are provided to allow a certain proportion of air to be supplied to the air-compressor from the outside. This is necessary to take the place of the air which escapes up the discharge-pipe. From said compressor lead pipes 3, opening at the bottominto the lower ends of receivers 4. 5 represents the suction-pipe having branches 6 connected with the receivers 41. Checkvalves 7 are provided at the bottoms of said receivers. From the tops of the receivers 4 lead the branches 8 of the Water-discharge pipe 9, there being also check-valves 10 at the tops of the receivers. From the compressed-air pipes 3 short pipes 11 conduct to the branches 8, having therein the check valves 12.

In the modification shown in Figs. 3 to 6 the two air-pipes 3 connect with a single pipe 13, whichis conducted down in theinterior of the water-discharge pipe 14. There is provided at the juncture of the pi es 3 and 13 a valve 15, which is automatica 1y actuated by the movement of the piston, through a lug 16 reciprocating therewith, to disconnect the pipe 13 from oneof the airipes 3 and connect it with the other, there y first exhausting'the air in the pipe 13 until the piston has traveled a portion of its stroke and then shutting 067 the exhaust and forcing compressed air into this pipe 13. The pipe 13 at its lower end is connected with a conduit 17, formed integral with the top 18 of the receiver 19, said receiver having also a compressed-air conduit 20 formed integral therewith and discharging at the bottom thereof, as shown at 21. 22 is a suction-pipe for en plying said receiver with water, and 23 an 24 are the check-valves at the upper and lower ends of said receiver, correspond-s ing to the check-valves 10 and 7 in the first modification. The conduit 17 opens direct into the discharge-pipe 1 1, havinga checkvalve 30.

The main principle involved in my invention will be best understood by reference to the diagrammatic view, Fig, 7, which represents a small experimental apparatus constructed entirely of glass for the purpose of viewing the position and movements of the liqui therein. In this figure, 25 represents a horizontal compressed-air tube, and 26 a vertical liquid-discharge tube into which the air-tube 25 enters at 27 Said tube 26 is bent round at its lower end, and the upwardly-extending portion 28 is again connected with the airtube 25 at a polnt 29 nearer the entrance of said tube 25. Now let the tube 26'be filled with water up to any level below the junctures 29 and 27 with the horizontal air-tube. Then let the experimenter blow gently into' the tube 25. It will be found that the level of the water in the further branch 26 of the tube is higher than in the nearer branch 28. The explanation of this is obvious. When compressed air is flowing along a pipe and out therefrom into a region of less pressure, as the atmosphere, the velocity increases and the pressure falls as it approaches its outlet. The pressure at the point 29 is therefore greater than at the point 27. It is evident that the pressure on the liquids in the branches 28 and 26 are respectively equal to the pressure at the points 29 and 27, for until the water changes its level there is no ICC LII

movement of air between the point 29 and the surface of the liquid in the branch28, and, therefore, the 1 pressures at the point 29 and at the surface 0 the liquid must be the same. So also in the branch 26 the pressure at the point 27 must be the same as at the surface of the liquid. Since, therefore, the pressure at the point 29 is greater than at the point 27, the pressure on the liquid in the branch 28 is greater than that in the branch 26, wherefore the water falls in the branch 28 and rises inthe branch 26. In fact, if the experimenter blows vigorously, he can in this way drive nearly all the'water out of the bent tube. The effect is the greater when the tube 26 is of greater diameter "than the tube 25, because then the air in entering the tube 26 at the point 27 so much more rapidly expands, and therefore falls so much lower in pressure, causing a correspondingly greater. difference between the pressures on the liquid in the pressure branch 28 and the edu'ction branch 26.

Considering now the operation of the pump shown in Figs. 1 and 2, it will readily be seen that this pump will first operate as a double-acting suction-pump only until a suflicient amount of water has been-sucked into each receiver to ass through the checkvalves 10. Thencef drth it will act as a force-pump on the principle illustrated by the experimental apparatus shown in Fig. 7. Each side then operates in turn as a force pump, the other side at the same time acting as a suction-pump. To obtain a clear idea as to how this apparatus, illustrated in Figs. 1, and 2, differs from an ordinary forcepump, let us return to the experimental apparatus illustrated in Fig. 7, and let us first imagine that the pipe 25 was completely stopped between the points 29 and 27. Then evidently upon blowing into the pipe 25 all the air has to pass down the branch 28 and the Whole of the water unmingled with air is forced upward through the pipe 26. Now let us make the contrary supposition that the two points 29 and 27 are brought close together and the pipe 26 is of no greater diameter than the pipe 25. Under these conditions the difference in the pressures at the points 29 and 27 is so small that there is substantially no diiferenceof levels of the water in the branches 28 and 26. Then no water at all rises in the pipe 26, but only air passes upward therethrough'. Between these two extremes, then, when, on the one hand, all water and no air rises, and, on the other hand, all air and no water rises, it is possible to proportion the amounts of air and water to any desired ratio by properly adjusting the degree of freedom with which the air passes from the point of junction with the pressure branch to the point of junction with the eduction branch, for upon this degree of freedom depends the difference of pressures at 1 the two points, upon which again depends the difference of levels in the two branches. Two things which are necessary for the practical success of the apparatus, as shown, are also of advantage in increasing this difference of level. First, the check-valves 12 are necessary, because the movement is in termittent, alternately suction and compression, and the check-valves are necesnecessary that the water discharge pipe should be of greater diameter than the compressed-air pipe, the friction of water being 'so much greater than that of air. Both of these features of construction create a difference of pressure at the two junctions. The principle of operation will be the same when there is a quantity of water in the pipe 9 above the check-valve 12. Suppose, for instance, that there are twenty feet of water above said check-valve and twenty-four feet above the check-valve 10. Adding to these lent feet of water (thirty-two feet approximately) we have a head of fifty-two feet at the check-valve 12 and fifty-six feet at the check-valve 10. Now suppose the maximum compressed-air pressure is a head of one hundred" feet of water. The air escaping through the'valve 12 will immediately fall in pressure to fifty-two feet of water and the downward pressure on the check-valve 10 will still be fifty-six feet of water, while the upward pressure will be one hundred feet of water, so that the checkvalve 10 will be lifted and water will pass upward. It is to be remembered that at the beginning of each compression-stroke the water will stand in the pipe 3 at the level of the check-valve 10, making the pressure on the under side of the check-valve the same as that in the compressed-air pipe. Supposing now that the amount of water in the pipe 9 has reached its maximum limit, which, assuming that the maximum limit of the compressed-air pressure is one hundred feet head of water, will be sixty-eight feet above the check-valve 10, (deducting thirty-two feet for the atmosphere,) an escape for the water from this pipe 9 must now be provided. The actual height of the pipe 9 up to this point of escape will depend upon the proportions of air and water. As has been already explained, if it is desired to increase the height to which the water is raised without increasing the pressure from the air-compressor this can only be done by increasing-the ratio of air to water. Assuming that such an escape has been provided what will now be the modus 'operandi? The downward pressure on the check-valve 10 is one hundred feet of wa ter, which is equal to the maximum pressure;

valve 10say four feet above-the pressure but owing to the valve 12 being above the sary to allow of the suction; secondly, it is the weight of the atmosphere in its equivafeet. tion is that water cannow be lifted to great -to 6 operates on the same principle. For in stance, suppose that in the pipe 13 there are twent feet of water above the check-valve 30 an twenty-four feet above the check-valve 23. Adding the weight of the atmosphere, this gives fifty-two feet pressure at the formerpoint and fifty-six .feet at the latter. As soon as the compressed-air pressure rises above fifty-six feet of water the valve 23 will rise, for the pressure on the top of said valve 23 will not exceed fifty-six feet of water, because as soon 'as any air escapes through the valve 30 it falls to a pressure of fiftytwov feet of water, making a pressure on the top of the valve 23 of not more than fifty-six The main advantage of this construcheights by compressed air of comparatively low pressure; but addition this apparatus is of greater efficiency than those using high pressure of com ressed air, for there is not so much loss 0 energy by conversion into wasted heat. Thus by means of this apparatus not only can liquids be umped from wells too deep to be success lly pumped out by the old methods, but even in comparatively shallow wells the efficiency of the present apparatus is greater. The expansion of the ascending strata of air in the pipe 9 serves to more rapidly force out the superincumbent strata of water, and thus lighten the load.

The main features of novelty of my invention which constitute its advance overthe prior art are as follows:

First, the ability to pum water to a great height witha comparative y low ressure ,sayto a height of one thousand feet with a pressure of one hundred pounds only and this with only a single opening direct from the compressed-air pipe to the water-discharge sha i e, said 0 enin bein 'ust above the to h eck-valve of tfie recEiier-is due to thi; fact thatthesize of the passa efrom the compressed-air pi 1s soregulate relatively to the height of sald latter pipe-and to the pressure of the compressed air that a sufficiently large proportion of air.to theliquid is admitted into the discharge-pipe to distribute the liquid throughout the whole length of said pipe and interpose air thereinto such an extent that the weight of the entire amount of liquid therein amount of li uid in the e to the liqui -discharge pipe.

.not overbalance the pressure of thecompressed air. For instance, supposing that the height of the discharge-pipe is one thousand feet and the pressure of the comhundred pounds, which pressed air 1s one would ordinarily balance only about two hundred and twenty-five feet of water, then I make the passage from the compressed-air pipe to the liquid-discharge pipe sufficiently arge to admit a sufficient amount of air in proportion to the liquid that the whole one thousand feet of pipe would,i allowed to fall into a solid column, be not more. than two hundred and twenty-five feet in height. v

A second. 'mportant feature of my invention is the fact that, in conjunction with the receiver, the check-valve admitting the liq; uid to the receiver, the liquid-discharge pipe from the receiver, the check-valve between them, and the se arate communications from the compresse -air pipe to the receiver and to the li uid-discharge pipe, the latter passage, is suffi st'ructed that the compressed air can pass therethrough at each impulse in a sufficiently large roportion to the amount of liquid forced b such impulse from the receiver into the discharge-pipe so as to form a solid col- .umn or piston of air in theliquid-diseharge pipe, completely se aratin two such columns or pistons of iquid t erein. By this construction the air has its greatest efficiency inraising or driving the water before it as it expands and rises to the top ofthe dischargeh third important feature of my invention is that I produce alternately positive and negative pressures in the compressed-air pipe. By a negative pressure is meant less than that. of the atmosphere, which produces a suction in the receiver, thus drawing with certainty and rapidity the water into the receiver to fill the same toprovide a fresh supply of water for the next impulse of compressed air. It\is important that these impulses of compressed air should follow each other quickly and uniformly, so as to keep the water in rapid upward motion to the top of the discharge-pipe. Otherwise,

if the water is allowed to fall back work that has been done inraising the water is lost; also, in sinking mines the water can be supplied to the receiver by suction only.

Fourthly, in the preferred form of my invention I- provide two receivers and two branch dischargeipes leading therefrom, each having its 0 eck-valve therein, and a common discharge-pipe into which the branch dischar epipes conduct, a compressed-air pipe eading to each receiver, and means for compressing theair alternately in said pipes. By this means I obtain, as with the third feature of my invention above menciently large, free, and unobtioned, a rapid succession of impulses in the discharge-pipe, keeping the water in rapidlyascending movement.

I am aware that it has been proposed to a height of twenty-five feet above the top check-valve, and the'other branch openings would be at distances of twenty-five feet apart successively upward. If a greater pressure of the compressed air were used, the distance between the top check-valve and the branch openings would be proportionately greater, the distance in each case being substantially that to which the pressure of the compressed air would raise a column of water. The principle of operation of this system was, in fact, as follows: The com pressed-air pressure of, say, fifteen pounds, was used to raise a column of water from the check-valve to a height of twenty-five feet, then another quantity of compressed air was admitted into the top of this column of water so raised to send it upward another twentyfive feet, then when the force of the compressed air in so raising the water was nearly exhausted another supply of compressed air was admitted to raise it a further twenty-five feet, and so on up to the top of the dischargepipe. This system, however, has, I believe, never comeinto practical use. The mechanical difficulties in carrying out this system appear to be too great; and while the system might be successful theoretically after once started it is not easy to see how it could be started, at least without an excessively high pressure. of compressed air to begin with, as on account of the discharge-pipe being empty of water at the commencement of operation the compressed air would too readily flow out thereinto, thus not providing sufficient pressure at the bottom. Furthermore, it was a special feature of this system that the air should enter the water-discharge pipe in minute streams or bubbles. Such streams and bubbles will not have the same effect in raising the water as when the air is admitted in sufficiently large quantities to form a solid column of air filling the whole width of the pipe beneath the water, and thus positively driving upward the water above it. In said system, again, no provision was made for a pair of receivers and branch discharge-pipes leading to a common discharge-pipe, nor could such provision have very well been made on account of the difficulty of having a double series of passages with check-valves connected with the discharge-pipes at intervals all the way from the receiver to the ,top. I am also aware that a system of elevating Water has been used in which a succession of alternating solid columns of pistons of air and liquid have been caused to ascend the discharge-pipe. Said columns have been formed by discharging compressed air into the open lower end of the discharge-pipe No receiver or check-valves were used in such a system, and it was therefore necessary to provide a head of water outside the dischargepipe to two-thirds the height of said pipe that is, to raise water one thousand feet the lower end of the discharge-pipe would have to be continued to a depth of two thousand feet below the surface of the water. There are very few mines or wells where such a condition of affairs exist, and therefore that system has a very limited application.

I claim 1. In a liquid-impelling apparatus, a receiver, a check-valve admitting the liquid to the receiver, a liquid-discharge pipe from the receiver, a check-valve between them, a compressed-air pipe having separate communications with the receiver and with the liquiddischarge pipe, and means'for producing alternately positive and negative pressures in the compressed-air pipe, substantially as described.

2. In a liquid-impelling apparatus, a receiver, a check-valve admitting the liquid to the receiver, a liquid-discharge pipe from the receiver, a check-valve between them, a compressed-air pipe having separate communications with the. receiver and with the liquiddischarge pipe, the passage fromthe compressed-air pipe to the liquid-discharge pipe being sufficiently large, free and unobstructed that the compressed air can pass therethrough at each impulse thereof in a sufiiciently large proportion to the amount of liquid forced by such impulse from the receiver into the discharge-pipe as to form a solid column or piston of air in the liquid-dischar e pipe, completely separating two such co umns or pistons of liquid therein, substantially as described.

3. In a liquid-impelling apparatus, a recciver a check-valve admitting the liquid to the receiver, a liquid-discharge pipr-v from the receiver, a check-valve between them, a compressed-air pipe having separate communications with the receiver and with the liquid- 'discharge pipe, the passage from the compressed-air pipe to the liquid-discharge pipe being sufficieutlylarge, free and unobstructed that the compressed air can pass therethrough at each impulse thereof in a sufficiently large pro ortion. to the amount of liquid forced by suc impulse from the receiver into the disapparatus, a receiver, a check-valve admitting the li uid to the receiver, a compressed-air pipe lea ing tov the receiver, means for compressing the air in size of the I pipe to the liquid-discharge pipe being so regsaid pipe, a liquid-dischar from the receiver, and a chec -valve between the discharge-pipe and the receiver, the compressed-air pi e opening into the dischargepipe above the chock-valve at a point rela tively near the receiver, and the size of the passage from the compressed-air pipe to the iquid-dischar e pipe being so regulated relatively to the eight of said latter pipe and the pressure of the compressed air that a sufficiently large proportion of air to liquid is admitted into the discharge-pipe to distribute the liquid through the" whole length of said pipe to such an extent that the weight of the entire amount of liquid therein shall not overbalance the pressure of the compressed air, substantially as described.

5. In a liquid-impelling apparatus, a receiver, a check-valve admitting the liquid to the receiver, a compressed-air pipe leading to the receiver, means for compressing the air in said pipe, a liquid-discharge pipe leading from the receiver, and a check-valve between the discharge-pipeand the receiver, the compressed-air pipe opening pipe at a point above said receiver, and the assage from the compressed-air ulated relatively to the'height ofsaid latter pipe and the pressure of the compressed air that a sufficiently large proportion of air to liquid is admitted into the discharge-pipe to distribute the liquid through the whole length of such pipe to such anextent that the weight of the entire amount of li uid shall not overbalance the pressure of t e compressed air, and means forproducingalternately positive and negative pressures in the compressed-air pipe, substantially as described.

6. In a liquid-impelling apparatus, a pair of receivers, checlevalves admitting the liquid to the receivers, a compressed-air pipe leading to each receiver, means tor producing alternately positive and negative pressures in the respective pipes, a branch liquid-discharge pipe leading from each receiver, a common discharge-pipe into which said branch pipes tween e'ach receiver and the discharge-pipe leading therefrom, the compressedair pipe opening into the corresponding branch discharge-pipe above the check-valve, substantially as described.

e pipe leading between each receiver into the discharge- 7 conduct, and a check-valve be- 7 In a liquid-impelling apparatus, a pair of receivers, check-valves admitting tlre liquid to the receivers, a compressed-air pipe I leading to each receiver, means for compressing the air alternately in said pi es, a branch liquid-discharge pipe leading i T om eachreeeiver, a common discharge-pipe into which said branch pipes conduct,and a check-valve between each receiver and the discharge-pipe leading therefrom, the compressed-air pipe opening-into the corresponding branch discharge-pipe above the check-valve, the passage from the compressed-air pipe to the liqui disch arge pipe being sufiiciently large, tree and unobstructed that the compressed air can pass therethrough at each impulse thereof in a sufliciently large proportion to the amount of liquid forced by such impulse from the receiver into the discharge-pipe as to forma solid column or piston of air in the liquid-dischar e pipe, completely separating twosuch co umns or pistons of liquid therein, substantially as described.

8. In a liquid mpelling apparatus, a pair of receivers, check-valves admitting the liquid to the receivers, a compressed-air pipe leading to each receiver, means for compressing the air alternately in said pipes, a branch liquid-discharge pipe leading from each receiver, a common discharge-pipe into which said branch pipes conduct, and a check-valve and the dischargepipe leading therefrom, the compressed-air pipe opening into the corresponding branch discharge-pipe above the check-valve and relatively near the receiver, the size of the passage from the compressed-air pipe to the liquid-discharge pipe being so regulated relatively to the height of said latter pipe and the pressure of the compressed air that a sufficiently large proportion of air to liquid is admitted into the discharge-pipe to distribute the liquid through the whole length of said pipe to such an extent that the weight of the entire amount of liquid therein shall not overbalance the pressure of the compressed air, substantially as described.

9. In a liquid-impelling apparatus, a receiver, a check-valve admitting the liquid to the receiver, a liquid-discharge pipe leading from the receiver, and a checlevalve between the discharge-pipe and the receiver, a compressed-air pipe and means for compressing the air therein, said compressed-air pipe opening into the discharge-pipe relatively near the receiver, and the size of the passage from the compressed-air pipe to the liquiddischargepipe being so regulated relatively to the height of said latter pipe and the pressure of the compressedair that a sufficiently large proportion of air to liquidis admitted into-the discharge-pipe to distribute the liquid through the whole length or said pipe to such an extent that the weight of the entire amount of liquid therein shall not overbalhand in the presence Of tWO subscribing Wit ance the pressure of the compressed air, and l nesses. means for applyin the force of the compressed air to force the liquid from the rel STARRETT' 5 ceiver into the dischargepipe, substantially Witnesses:

as described. FRANCIS M; WRIGHT,

In Witness whereof I have hereunto set my M. STUART. 

